There are several different tablet or small article feeding systems commonly used today. They are either large in size, slow in speed, or have feeding systems that are ganged and dependent to each other. The most common tablet or small article feeding systems are Vibratory “V” Chutes and trays; Vibratory Bowls; Fill by weight; Slat counters; Disc Counters; Roller Sorting Systems; Vacuum disc/Drum; Centrifugal Rotating Disc Counters, and the Rotating Dedicated Pocket Disc style.
The two Vibrating Styles of feeders are prone to make a lot of noise. As you increase the feed rate, the noise level increased as well. The vibration can damage the tablets by shaking them at such a high rate, and tend to produce a lot of tablet dust. This type of feeding system is inefficient as much of the energy of the vibrator is in lifting the article up vertically, then moving it forward. As the vibration rate increases, the tablet stability decreases as they start bouncing around uncontrollably.
Weight Counters, count by weight, and are less accurate than others as they cannot tell if a capsule is empty or if a partial tablet was passed. Every batch of tablets have a different amount of humidity, water content, so the tablet weight could vary. Also there are manufacture tablet weight and ingredient tolerances to consider. With the accumulation of all these possible errors, this type of counting is not the most accurate.
The Slat Counter is large and fast, but has many change parts and is difficult and time consuming to change over. Each different tablet size and shape must have dedicated expensive change parts. So this is why this machine is normally dedicated to one or only a few different tablet sizes.
The Disc Counter is large in size and has big dedicated change parts. A set of change parts must be made for each different tablet size and shape in which is expensive and requires a lot of storage space. Normally this style of machine is used for large production runs.
The Centrifugal Rotating Disc Counter, has a hopper in the middle of it and it feeds out tablets onto a horizontal rotating disc. As the disc rotates, the tablets are drawn towards the outer sides due to inertia. Then they exit the disc at its outer edge, and drops down due to gravity pass a count sensor.
This counting system is slow, and the disc is large in diameter, and care has to be given in order to prevent doubling up tablets to exit at the same time.
The Rotating Dedicated Pocket Disc Style counter does feed quickly, but requires a dedicated change part disc for each different tablet size and shape in which can be expensive. Also this type of counting system is large in size, especially if several of these disc are to be used for higher output speeds.
The Roller Sorting System does not space the tablets equally and does not ensure a distance between each article when discharging. The long length of the rollers are necessary in order to try to sort out the tablets in one single row with no doubling up at the discharge. The incline angle downwards towards the exit point causes the tablets to roll or to bunch up together at the exit point. Also it's difficult to stop quickly the flow of tablets due to gravity, inertia, and the tendency for round tablets wanting to keep rolling forward.
The Vacuum rotary Disc or Drum counter depends on obtaining a good positive vacuum. Tablets are sucked to the rotary disc or drum style and rotated around then dropped in front of a count sensor. These systems require a lot of air flow, vacuum, in which is noisy and expensive to produce. The vacuum levels is dependent, and could change, depending on how many tablets are covering the holes. Special dedicated change parts are required for the vacuum pockets on the vacuum discs. Also the size of the vacuum hole depends on the weight, feeding speed and size of each tablet.
One big concern today is the overall size of the machine. The industry is asking for machines that occupy less conveyor space and shorter in length in order to utilize there plant space more efficiently. Also the height of the machines are important as some people are shorter than others, and many times these machines require a step or staircase in order to fill the product hopper or to view the tablet sorting process.
Presently most tablet or small article counting machines are designed and built to one size. If you would like to increase production, you must purchase a new machine and place it beside the other one. There is no prevision for machine expansion. This is both very expensive, and could double your present conveyor space requirement and machine foot print.
The industry is trying to get away from using air, vacuum and vibration for tablet feeding due to the noise and dust that they produce, and the energy required. The industry is moving towards less and smaller dedicated change parts, to lower their costs and to improve change over times.
Most companies would like to keep growing in size and later increase their output from their existing counters. Instead of purchasing an entire new machine, many would rather purchase just the counting expansion modules necessary to add onto to their existing machine.
Also during production, if one article feeding lane or count sensor should fail, ideally it would be a benefit to continue with the production run by just closing down that one particular lane and not the entire machine. This is not true for most of these machines listed above.
All of these different counting machines are either large in size; have expensive change parts; run at slow speeds; not expandable or produce a lot of dust and noise. This is why this Belt Sorter System was designed to solve all these issues and concerns.